CVE-2026-9675

HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 65% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.5Exploit: NoneExposed: 0

A fix is available — apply it.

Impact: The undici WebSocket client enforces maxPayloadSize per-frame but does not enforce the cumulative size of fragmented uncompressed messages. A malicious WebSocket server can stream many small fragments that each pass per-frame validation but collectively exceed the configured limit, causing unbounded memory growth in the client process. The result is memory exhaustion and a denial of service.

Affected applications are those using the undici WebSocket client (new WebSocket(...)) that can be induced to connect to an attacker-controlled or compromised WebSocket endpoint.

This is a regression specific to undici 8.1.0. The 6.25.0 line shipped the equivalent cumulative check from the start and is unaffected. The 7.x line never had the maxPayloadSize feature and is also unaffected.

Patches: Upgrade to undici >= 8.5.0.

Workarounds: No workaround is available. The fix must be applied through an upgrade.

CVSS v3
7.5
EG Score
7.5(medium)
EG Risk
—
EPSS
34.8%
KEV
Not listed

Published

June 17, 2026

Last Modified

June 25, 2026

Advisory Details (2)

Auto-updated Jun 17, 2026
Patch available. Sources: github.
github Patch Available

undici WebSocket client vulnerable to denial of service via cumulative fragment bypass · Advisory · nodejs/undici · GitHub

https://github.com/nodejs/undici/security/advisories/GHSA-38rv-x7px-6hhq
generic

Security Advisories | OpenJS Foundation CVE Numbering Authority

https://cna.openjsf.org/security-advisories.html

Vendor Advisories for CVE-2026-9675(6)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(4)

Vendor / EcosystemFixed in / PatchReleasedSource
redhatnodejs24-main-24.16.0-1.hum12026-06-13redhat
redhatrust-main-1.96.0-1.hum12026-06-03redhat
redhatnodejs26-main-26.3.0-1.2.hum12026-06-02redhat
redhatnodejs25-main-25.9.0-1.1.hum12026-04-10redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
undici—8.5.0—

Weakness Classification(2)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 10× in last 7d / 75× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-22 14:08 UTCEPSS rescore
  2. 2026-07-21 15:25 UTCEPSS rescore
  3. 2026-07-21 15:25 UTCEPSS rescore
  4. 2026-07-20 17:08 UTCEPSS rescore
  5. 2026-07-19 02:29 UTCEPSS rescore
  6. 2026-07-18 10:04 UTCEPSS rescore
  7. 2026-07-17 03:19 UTCVendor advisory
  8. 2026-07-16 17:03 UTCEPSS rescore
  9. 2026-07-16 14:37 UTCVendor advisory
  10. 2026-07-16 01:48 UTCVendor advisory
  11. 2026-07-15 16:57 UTCEPSS rescore
  12. 2026-07-15 13:09 UTCVendor advisory
  13. 2026-07-15 02:00 UTCEPSS rescore
  14. 2026-07-15 00:19 UTCVendor advisory
  15. 2026-07-14 11:41 UTCVendor advisory
  16. 2026-07-13 22:59 UTCVendor advisory
  17. 2026-07-13 22:31 UTCEPSS rescore
  18. 2026-07-13 10:20 UTCVendor advisory
  19. 2026-07-13 06:13 UTCEPSS rescore
  20. 2026-07-12 21:37 UTCVendor advisory
  21. 2026-07-12 08:28 UTCVendor advisory
  22. 2026-07-12 05:46 UTCEPSS rescore
  23. 2026-07-11 19:49 UTCVendor advisory
  24. 2026-07-11 08:27 UTCEPSS rescore
  25. 2026-07-11 07:10 UTCVendor advisory
Show 64 more
  1. 2026-07-10 18:31 UTCVendor advisory
  2. 2026-07-10 05:43 UTCVendor advisory
  3. 2026-07-09 19:10 UTCEPSS rescore
  4. 2026-07-09 17:04 UTCVendor advisory
  5. 2026-07-09 01:53 UTCVendor advisory
  6. 2026-07-08 15:16 UTCEPSS rescore
  7. 2026-07-08 13:07 UTCVendor advisory
  8. 2026-07-07 23:56 UTCVendor advisory
  9. 2026-07-07 13:46 UTCEPSS rescore
  10. 2026-07-07 11:17 UTCVendor advisory
  11. 2026-07-06 21:48 UTCVendor advisory
  12. 2026-07-06 16:27 UTCEPSS rescore
  13. 2026-07-06 07:19 UTCVendor advisory
  14. 2026-07-06 02:23 UTCEPSS rescore
  15. 2026-07-05 18:37 UTCVendor advisory
  16. 2026-07-05 05:59 UTCVendor advisory
  17. 2026-07-05 02:31 UTCEPSS rescore
  18. 2026-07-04 16:15 UTCVendor advisory
  19. 2026-07-04 06:31 UTCEPSS rescore
  20. 2026-07-04 03:28 UTCVendor advisory
  21. 2026-07-03 14:02 UTCVendor advisory
  22. 2026-07-03 01:23 UTCVendor advisory
  23. 2026-07-02 12:44 UTCVendor advisory
  24. 2026-07-02 00:05 UTCVendor advisory
  25. 2026-07-01 15:07 UTCEPSS rescore
  26. 2026-07-01 11:26 UTCVendor advisory
  27. 2026-06-30 23:22 UTCEPSS rescore
  28. 2026-06-30 22:46 UTCVendor advisory
  29. 2026-06-30 10:06 UTCVendor advisory
  30. 2026-06-29 21:10 UTCVendor advisory
  31. 2026-06-29 14:06 UTCEPSS rescore
  32. 2026-06-29 08:32 UTCVendor advisory
  33. 2026-06-28 19:52 UTCVendor advisory
  34. 2026-06-28 14:07 UTCEPSS rescore
  35. 2026-06-28 07:13 UTCVendor advisory
  36. 2026-06-28 04:56 UTCEPSS rescore
  37. 2026-06-27 18:34 UTCVendor advisory
  38. 2026-06-27 05:55 UTCVendor advisory
  39. 2026-06-27 03:08 UTCEPSS rescore
  40. 2026-06-26 17:16 UTCVendor advisory
  41. 2026-06-26 04:38 UTCVendor advisory
  42. 2026-06-25 15:57 UTCVendor advisory
  43. 2026-06-25 13:50 UTCEPSS rescore
  44. 2026-06-25 03:18 UTCVendor advisory
  45. 2026-06-24 14:38 UTCVendor advisory
  46. 2026-06-24 14:05 UTCEPSS rescore
  47. 2026-06-24 01:59 UTCVendor advisory
  48. 2026-06-23 21:33 UTCEPSS rescore
  49. 2026-06-23 13:19 UTCVendor advisory
  50. 2026-06-23 00:37 UTCVendor advisory
  51. 2026-06-22 14:25 UTCEPSS rescore
  52. 2026-06-22 11:56 UTCVendor advisory
  53. 2026-06-21 23:10 UTCVendor advisory
  54. 2026-06-21 14:56 UTCEPSS rescore
  55. 2026-06-21 10:31 UTCVendor advisory
  56. 2026-06-21 01:59 UTCEPSS rescore
  57. 2026-06-20 21:51 UTCVendor advisory
  58. 2026-06-20 09:13 UTCVendor advisory
  59. 2026-06-19 20:33 UTCVendor advisory
  60. 2026-06-19 19:26 UTCEPSS rescore
  61. 2026-06-19 07:54 UTCVendor advisory
  62. 2026-06-18 17:52 UTCEPSS rescore
  63. 2026-06-17 17:52 UTCEG score recompute
  64. 2026-06-17 17:52 UTCNVD updatefirst tracked

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2026-9675?
CVE-2026-9675 is a high vulnerability published on June 17, 2026. Impact: The undici WebSocket client enforces maxPayloadSize per-frame but does not enforce the cumulative size of fragmented uncompressed messages. A malicious WebSocket server can stream many small fragments that each pass per-frame validation but collectively exceed the configured limit, causing…
When was CVE-2026-9675 disclosed?
CVE-2026-9675 was first published in the National Vulnerability Database on June 17, 2026, with the most recent update on June 25, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-9675 actively exploited?
CVE-2026-9675 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 34.8% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-9675?
CVE-2026-9675 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-9675?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-9675, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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